The present invention relates to the technical field of taking a breast's radiation image, that is, mammography, more particularly, to a breast's radiation image taking apparatus, that is, a mammography apparatus, that enables the radiation image of a large breast to be taken on a small radiation-receiving plane, as well as a method of taking a breast's radiation image, that is, a mammography.
In breast cancer screening, the success rate of early detection that is achieved through physical examination by inspection and palpation only is improved if it is combined with mammography by a radiation image taking apparatus solely intended for breasts (which is hereinafter referred to as a breast imaging apparatus); hence, breast cancer screening that is currently practiced involves the use of a breast imaging apparatus in addition to (or in place of) inspection and palpation.
The breast imaging apparatus comprises an imaging table enclosing a radiation image recording medium (which is hereinafter referred to as an imaging medium); to operate it, the breast is placed on the imaging table, compressed with a press plate, irradiated with a radiation from the press plate side; the radiation transmitted through the breast is received by the imaging medium and its radiation image is taken on the imaging medium.
The conventional breast imaging apparatus has been such that a radiation image converting panel (commonly called IP) that employs a stimulable phosphor or an X-ray film is used as the imaging medium and accommodated in a light-shielding case called a cassette, which in turn is loaded at a specified position in the imaging table for taking a radiation image of the breast.
A new model of breast imaging apparatus is recently increasing in number; an IP, a means of reading the radiation image taken/recorded on the IP, and a detector called a flat panel detector that performs conversion (photoelectric conversion) of a radiation to an image are fixedly installed within the imaging table and a radiation image that is taken of the breast is displayed on a screen or transferred to an external computer.